/**
 * @fileoverview Main CLI object.
 * @author Nicholas C. Zakas
 */

"use strict";

/*
 * NOTE: The CLI object should *not* call process.exit() directly. It should only return
 * exit codes. This allows other programs to use the CLI object and still control
 * when the program exits.
 */

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const fs = require("node:fs"),
    path = require("node:path"),
    { promisify } = require("node:util"),
    { LegacyESLint } = require("./eslint"),
    { ESLint, shouldUseFlatConfig, locateConfigFileToUse } = require("./eslint/eslint"),
    createCLIOptions = require("./options"),
    log = require("./shared/logging"),
    RuntimeInfo = require("./shared/runtime-info"),
    { normalizeSeverityToString } = require("./shared/severity");
const { Legacy: { naming } } = require("@eslint/eslintrc");
const { ModuleImporter } = require("@humanwhocodes/module-importer");
const debug = require("debug")("eslint:cli");

//------------------------------------------------------------------------------
// Types
//------------------------------------------------------------------------------

/** @typedef {import("./eslint/eslint").ESLintOptions} ESLintOptions */
/** @typedef {import("./eslint/eslint").LintMessage} LintMessage */
/** @typedef {import("./eslint/eslint").LintResult} LintResult */
/** @typedef {import("./options").ParsedCLIOptions} ParsedCLIOptions */
/** @typedef {import("./shared/types").Plugin} Plugin */
/** @typedef {import("./shared/types").ResultsMeta} ResultsMeta */

//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------

const mkdir = promisify(fs.mkdir);
const stat = promisify(fs.stat);
const writeFile = promisify(fs.writeFile);

/**
 * Loads plugins with the specified names.
 * @param {{ "import": (name: string) => Promise<any> }} importer An object with an `import` method called once for each plugin.
 * @param {string[]} pluginNames The names of the plugins to be loaded, with or without the "eslint-plugin-" prefix.
 * @returns {Promise<Record<string, Plugin>>} A mapping of plugin short names to implementations.
 */
async function loadPlugins(importer, pluginNames) {
    const plugins = {};

    await Promise.all(pluginNames.map(async pluginName => {

        const longName = naming.normalizePackageName(pluginName, "eslint-plugin");
        const module = await importer.import(longName);

        if (!("default" in module)) {
            throw new Error(`"${longName}" cannot be used with the \`--plugin\` option because its default module does not provide a \`default\` export`);
        }

        const shortName = naming.getShorthandName(pluginName, "eslint-plugin");

        plugins[shortName] = module.default;
    }));

    return plugins;
}

/**
 * Predicate function for whether or not to apply fixes in quiet mode.
 * If a message is a warning, do not apply a fix.
 * @param {LintMessage} message The lint result.
 * @returns {boolean} True if the lint message is an error (and thus should be
 * autofixed), false otherwise.
 */
function quietFixPredicate(message) {
    return message.severity === 2;
}

/**
 * Predicate function for whether or not to run a rule in quiet mode.
 * If a rule is set to warning, do not run it.
 * @param {{ ruleId: string; severity: number; }} rule The rule id and severity.
 * @returns {boolean} True if the lint rule should run, false otherwise.
 */
function quietRuleFilter(rule) {
    return rule.severity === 2;
}

/**
 * Translates the CLI options into the options expected by the ESLint constructor.
 * @param {ParsedCLIOptions} cliOptions The CLI options to translate.
 * @param {"flat"|"eslintrc"} [configType="eslintrc"] The format of the
 *      config to generate.
 * @returns {Promise<ESLintOptions>} The options object for the ESLint constructor.
 * @private
 */
async function translateOptions({
    cache,
    cacheFile,
    cacheLocation,
    cacheStrategy,
    config,
    configLookup,
    env,
    errorOnUnmatchedPattern,
    eslintrc,
    ext,
    fix,
    fixDryRun,
    fixType,
    flag,
    global,
    ignore,
    ignorePath,
    ignorePattern,
    inlineConfig,
    parser,
    parserOptions,
    plugin,
    quiet,
    reportUnusedDisableDirectives,
    reportUnusedDisableDirectivesSeverity,
    resolvePluginsRelativeTo,
    rule,
    rulesdir,
    stats,
    warnIgnored,
    passOnNoPatterns,
    maxWarnings
}, configType) {

    let overrideConfig, overrideConfigFile;
    const importer = new ModuleImporter();

    if (configType === "flat") {
        overrideConfigFile = (typeof config === "string") ? config : !configLookup;
        if (overrideConfigFile === false) {
            overrideConfigFile = void 0;
        }

        const languageOptions = {};

        if (global) {
            languageOptions.globals = global.reduce((obj, name) => {
                if (name.endsWith(":true")) {
                    obj[name.slice(0, -5)] = "writable";
                } else {
                    obj[name] = "readonly";
                }
                return obj;
            }, {});
        }

        if (parserOptions) {
            languageOptions.parserOptions = parserOptions;
        }

        if (parser) {
            languageOptions.parser = await importer.import(parser);
        }

        overrideConfig = [{
            ...Object.keys(languageOptions).length > 0 ? { languageOptions } : {},
            rules: rule ? rule : {}
        }];

        if (reportUnusedDisableDirectives || reportUnusedDisableDirectivesSeverity !== void 0) {
            overrideConfig[0].linterOptions = {
                reportUnusedDisableDirectives: reportUnusedDisableDirectives
                    ? "error"
                    : normalizeSeverityToString(reportUnusedDisableDirectivesSeverity)
            };
        }

        if (plugin) {
            overrideConfig[0].plugins = await loadPlugins(importer, plugin);
        }

    } else {
        overrideConfigFile = config;

        overrideConfig = {
            env: env && env.reduce((obj, name) => {
                obj[name] = true;
                return obj;
            }, {}),
            globals: global && global.reduce((obj, name) => {
                if (name.endsWith(":true")) {
                    obj[name.slice(0, -5)] = "writable";
                } else {
                    obj[name] = "readonly";
                }
                return obj;
            }, {}),
            ignorePatterns: ignorePattern,
            parser,
            parserOptions,
            plugins: plugin,
            rules: rule
        };
    }

    const options = {
        allowInlineConfig: inlineConfig,
        cache,
        cacheLocation: cacheLocation || cacheFile,
        cacheStrategy,
        errorOnUnmatchedPattern,
        fix: (fix || fixDryRun) && (quiet ? quietFixPredicate : true),
        fixTypes: fixType,
        ignore,
        overrideConfig,
        overrideConfigFile,
        passOnNoPatterns
    };

    if (configType === "flat") {
        options.ignorePatterns = ignorePattern;
        options.stats = stats;
        options.warnIgnored = warnIgnored;
        options.flags = flag;

        /*
         * For performance reasons rules not marked as 'error' are filtered out in quiet mode. As maxWarnings
         * requires rules set to 'warn' to be run, we only filter out 'warn' rules if maxWarnings is not specified.
         */
        options.ruleFilter = quiet && maxWarnings === -1 ? quietRuleFilter : () => true;
    } else {
        options.resolvePluginsRelativeTo = resolvePluginsRelativeTo;
        options.rulePaths = rulesdir;
        options.useEslintrc = eslintrc;
        options.extensions = ext;
        options.ignorePath = ignorePath;
        if (reportUnusedDisableDirectives || reportUnusedDisableDirectivesSeverity !== void 0) {
            options.reportUnusedDisableDirectives = reportUnusedDisableDirectives
                ? "error"
                : normalizeSeverityToString(reportUnusedDisableDirectivesSeverity);
        }
    }

    return options;
}

/**
 * Count error messages.
 * @param {LintResult[]} results The lint results.
 * @returns {{errorCount:number;fatalErrorCount:number,warningCount:number}} The number of error messages.
 */
function countErrors(results) {
    let errorCount = 0;
    let fatalErrorCount = 0;
    let warningCount = 0;

    for (const result of results) {
        errorCount += result.errorCount;
        fatalErrorCount += result.fatalErrorCount;
        warningCount += result.warningCount;
    }

    return { errorCount, fatalErrorCount, warningCount };
}

/**
 * Check if a given file path is a directory or not.
 * @param {string} filePath The path to a file to check.
 * @returns {Promise<boolean>} `true` if the given path is a directory.
 */
async function isDirectory(filePath) {
    try {
        return (await stat(filePath)).isDirectory();
    } catch (error) {
        if (error.code === "ENOENT" || error.code === "ENOTDIR") {
            return false;
        }
        throw error;
    }
}

/**
 * Outputs the results of the linting.
 * @param {ESLint} engine The ESLint instance to use.
 * @param {LintResult[]} results The results to print.
 * @param {string} format The name of the formatter to use or the path to the formatter.
 * @param {string} outputFile The path for the output file.
 * @param {ResultsMeta} resultsMeta Warning count and max threshold.
 * @returns {Promise<boolean>} True if the printing succeeds, false if not.
 * @private
 */
async function printResults(engine, results, format, outputFile, resultsMeta) {
    let formatter;

    try {
        formatter = await engine.loadFormatter(format);
    } catch (e) {
        log.error(e.message);
        return false;
    }

    const output = await formatter.format(results, resultsMeta);

    if (outputFile) {
        const filePath = path.resolve(process.cwd(), outputFile);

        if (await isDirectory(filePath)) {
            log.error("Cannot write to output file path, it is a directory: %s", outputFile);
            return false;
        }

        try {
            await mkdir(path.dirname(filePath), { recursive: true });
            await writeFile(filePath, output);
        } catch (ex) {
            log.error("There was a problem writing the output file:\n%s", ex);
            return false;
        }
    } else if (output) {
        log.info(output);
    }

    return true;
}

//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------

/**
 * Encapsulates all CLI behavior for eslint. Makes it easier to test as well as
 * for other Node.js programs to effectively run the CLI.
 */
const cli = {

    /**
     * Calculates the command string for the --inspect-config operation.
     * @param {string} configFile The path to the config file to inspect.
     * @param {boolean} hasUnstableTSConfigFlag `true` if the `unstable_ts_config` flag is enabled, `false` if it's not.
     * @returns {Promise<string>} The command string to execute.
     */
    async calculateInspectConfigFlags(configFile, hasUnstableTSConfigFlag) {

        // find the config file
        const {
            configFilePath,
            basePath
        } = await locateConfigFileToUse({ cwd: process.cwd(), configFile }, hasUnstableTSConfigFlag);

        return ["--config", configFilePath, "--basePath", basePath];
    },

    /**
     * Executes the CLI based on an array of arguments that is passed in.
     * @param {string|Array|Object} args The arguments to process.
     * @param {string} [text] The text to lint (used for TTY).
     * @param {boolean} [allowFlatConfig=true] Whether or not to allow flat config.
     * @returns {Promise<number>} The exit code for the operation.
     */
    async execute(args, text, allowFlatConfig = true) {
        if (Array.isArray(args)) {
            debug("CLI args: %o", args.slice(2));
        }

        /*
         * Before doing anything, we need to see if we are using a
         * flat config file. If so, then we need to change the way command
         * line args are parsed. This is temporary, and when we fully
         * switch to flat config we can remove this logic.
         */

        const usingFlatConfig = allowFlatConfig && await shouldUseFlatConfig();

        debug("Using flat config?", usingFlatConfig);

        if (allowFlatConfig && !usingFlatConfig) {
            process.emitWarning("You are using an eslintrc configuration file, which is deprecated and support will be removed in v10.0.0. Please migrate to an eslint.config.js file. See https://eslint.org/docs/latest/use/configure/migration-guide for details. An eslintrc configuration file is used because you have the ESLINT_USE_FLAT_CONFIG environment variable set to false. If you want to use an eslint.config.js file, remove the environment variable. If you want to find the location of the eslintrc configuration file, use the --debug flag.", "ESLintRCWarning");
        }

        const CLIOptions = createCLIOptions(usingFlatConfig);

        /** @type {ParsedCLIOptions} */
        let options;

        try {
            options = CLIOptions.parse(args);
        } catch (error) {
            debug("Error parsing CLI options:", error.message);

            let errorMessage = error.message;

            if (usingFlatConfig) {
                errorMessage += "\nYou're using eslint.config.js, some command line flags are no longer available. Please see https://eslint.org/docs/latest/use/command-line-interface for details.";
            }

            log.error(errorMessage);
            return 2;
        }

        const files = options._;
        const useStdin = typeof text === "string";

        if (options.help) {
            log.info(CLIOptions.generateHelp());
            return 0;
        }
        if (options.version) {
            log.info(RuntimeInfo.version());
            return 0;
        }
        if (options.envInfo) {
            try {
                log.info(RuntimeInfo.environment());
                return 0;
            } catch (err) {
                debug("Error retrieving environment info");
                log.error(err.message);
                return 2;
            }
        }

        if (options.printConfig) {
            if (files.length) {
                log.error("The --print-config option must be used with exactly one file name.");
                return 2;
            }
            if (useStdin) {
                log.error("The --print-config option is not available for piped-in code.");
                return 2;
            }

            const engine = usingFlatConfig
                ? new ESLint(await translateOptions(options, "flat"))
                : new LegacyESLint(await translateOptions(options));
            const fileConfig =
                await engine.calculateConfigForFile(options.printConfig);

            log.info(JSON.stringify(fileConfig, null, "  "));
            return 0;
        }

        if (options.inspectConfig) {

            log.info("You can also run this command directly using 'npx @eslint/config-inspector@latest' in the same directory as your configuration file.");

            try {
                const flatOptions = await translateOptions(options, "flat");
                const spawn = require("cross-spawn");
                const flags = await cli.calculateInspectConfigFlags(flatOptions.overrideConfigFile, flatOptions.flags ? flatOptions.flags.includes("unstable_ts_config") : false);

                spawn.sync("npx", ["@eslint/config-inspector@latest", ...flags], { encoding: "utf8", stdio: "inherit" });
            } catch (error) {
                log.error(error);
                return 2;
            }

            return 0;
        }

        debug(`Running on ${useStdin ? "text" : "files"}`);

        if (options.fix && options.fixDryRun) {
            log.error("The --fix option and the --fix-dry-run option cannot be used together.");
            return 2;
        }
        if (useStdin && options.fix) {
            log.error("The --fix option is not available for piped-in code; use --fix-dry-run instead.");
            return 2;
        }
        if (options.fixType && !options.fix && !options.fixDryRun) {
            log.error("The --fix-type option requires either --fix or --fix-dry-run.");
            return 2;
        }

        if (options.reportUnusedDisableDirectives && options.reportUnusedDisableDirectivesSeverity !== void 0) {
            log.error("The --report-unused-disable-directives option and the --report-unused-disable-directives-severity option cannot be used together.");
            return 2;
        }

        const ActiveESLint = usingFlatConfig ? ESLint : LegacyESLint;
        const eslintOptions = await translateOptions(options, usingFlatConfig ? "flat" : "eslintrc");
        const engine = new ActiveESLint(eslintOptions);
        let results;

        if (useStdin) {
            results = await engine.lintText(text, {
                filePath: options.stdinFilename,

                // flatConfig respects CLI flag and constructor warnIgnored, eslintrc forces true for backwards compatibility
                warnIgnored: usingFlatConfig ? void 0 : true
            });
        } else {
            results = await engine.lintFiles(files);
        }

        if (options.fix) {
            debug("Fix mode enabled - applying fixes");
            await ActiveESLint.outputFixes(results);
        }

        let resultsToPrint = results;

        if (options.quiet) {
            debug("Quiet mode enabled - filtering out warnings");
            resultsToPrint = ActiveESLint.getErrorResults(resultsToPrint);
        }

        const resultCounts = countErrors(results);
        const tooManyWarnings = options.maxWarnings >= 0 && resultCounts.warningCount > options.maxWarnings;
        const resultsMeta = tooManyWarnings
            ? {
                maxWarningsExceeded: {
                    maxWarnings: options.maxWarnings,
                    foundWarnings: resultCounts.warningCount
                }
            }
            : {};

        if (await printResults(engine, resultsToPrint, options.format, options.outputFile, resultsMeta)) {

            // Errors and warnings from the original unfiltered results should determine the exit code
            const shouldExitForFatalErrors =
                options.exitOnFatalError && resultCounts.fatalErrorCount > 0;

            if (!resultCounts.errorCount && tooManyWarnings) {
                log.error(
                    "ESLint found too many warnings (maximum: %s).",
                    options.maxWarnings
                );
            }

            if (shouldExitForFatalErrors) {
                return 2;
            }

            return (resultCounts.errorCount || tooManyWarnings) ? 1 : 0;
        }

        return 2;
    }
};

module.exports = cli;
